1. Field of Invention
This invention is relate to the field of display technology. It primarily involves an optimized omni-directional display system of integrated display which is capable of providing constant omni-directional display effect through applying the effect of visual persistence.
2. Description of Related Arts
Methods and Devices for Omni-Directional Display contains current technologies and presents an invention (It has acquired Chinese and American patent right; Patent No.: ZL92108510.9 and U.S. Pat. No. 5,450,094A) of the inventor at early stage. This invention provides audience with such an unprecedented visual effect that observers at any position around the device can feel that they are squarely facing the central front part of pictures on the display. Under the effect of visual persistence of eyes, this unprecedented visual effect is obtained by making pictures on a display fitted with a blankoff device reflect on people's eyes repeatedly at imperceptible speed within the time limit of visual persistence. Blankoff device is capable of restricting observable angles, namely, making any of pixels on a display viewable to observers only when they are squarely facing the pixel. Accordingly, what an observer can view is an integral picture facing him precisely, which is comprised of all pixels precisely facing the observer. Due to the effect of blankoff device, pixels forming the same pictures are not viewed simultaneously by all observers. In contrast, they are scanned on eyes at imperceptible speed.
It is owing to the restriction of blankoff device on people's observing angles that they can see a frontal, non-overlapped and clear picture. However, its defect also lies in the restriction. When restricting observing angles, blankoff device makes restriction on observing duration, for when pixels on a display rotate for one circle, they can be viewed by observers for merely one time in a twinkle. Pixels are blanked off at most time, which results in the substantial reduction of brightness of a display. With its unique display characteristics, omni-directional display device is especially applicable to large-scale public places, e.g. large-scale expo, science & technology hall, museum, hotel, air harbor, central part of great hall in station and plaza. Since these public places are provided with comparatively bright background, they establish higher requirements for the brightness of display so that it can adapt to the environment and conform to requirements of observers. However, the existing varieties of display materials such as liquid crystal, light-emitting diode, plasma and organic luminophor are of limited brightness (especially in comparison with the omni-directional display device). Despite large-scale enterprises and research institutions specialized in this field in many countries have been making efforts to improve brightness of these materials, they haven't made considerable progress in this regard so far. More importantly, displays used in large-scale public places are required to be large-sized (e.g. its diagonal line is as long as 100 cm or above), so that they can be viewed simultaneously by different observers. Simulated tests and actual measurement of sample device performed for many times by the inventor have indicated that in order to make twinkles generated at the time of picture replacement imperceptible to observers, it is advisable to control the frequency of picture replacement at a rate of approx. 24 pieces per second. To obtain this, it is preferred that the rotary speed of rotating part fitted with only one display should be controlled at 24 circles per second. Only in this way can we achieve anticipated display effect. In case pictures are replaced at over-slow speed, observers will perceive twinkles of pictures and therefore the visual effect will be deteriorated. For instance, the rotating speed of external terminal line in a large-sized device with 1.5 m external rotating diameter will exceed 100 m/s when the rotating speed of the device is 24 circles per second. To enable the device to equally bear enormous effect of centrifugal force, it is crucial to give top priority to dynamic equilibrium of mechanism and allocation of inherent stress, which are complicated and require high cost.